They soared our skies during most of the Mesozoic — from the late Triassic to the end of the Cretaceous (228 to 66 million years ago).
By the end of the Cretaceous, they had grown to giants and one of their brethren, Quetzalcoatlus, a member of the family Azhdarchidae, boasts being the largest known flying animal that ever lived.
They were the earliest vertebrates known to have evolved powered flight. Their wings were formed by a membrane of skin, muscle, and other tissues stretching from the ankles to a dramatically lengthened fourth finger.
